Carabiners Break?!?!?

rogerbenton wrote: hey 20kn, where can we find tests of sun exposed slings?

http://www.blackdiamondequipment.com/en-us/journal/climb//qc-lab-old-fixed-slings-in-trees

little bit of info there.

There is definitely a lot more work that could be done with the topic though.

yeah, that battery acid test should be a shocker

Tayte Campbell,

Microcracks? Seriously? From being dropped? They don't exist. Ever. Sometimes carabiners will develop a crack from stress corrosion (or sometimes "Chlorine Stress Corrosion") but those cracks are always visible.

We tested carabiners that free-fell from the top of El Cap and they met spec. When Rock and Ice magazine ran a test on dropped carabiners, they found no reduction in the strength.

A quick search will find you lots of results.

Better to worry about the phenomena that actually kills climbers.

Mal

Does your study have to be about equipment failure? Or could it be about something else?

I'd like to see if anyone can come up with a decent study of climbing-related accident and fatality rates (i.e. accident/fatality rate per climbing day or per climber-year). Everything I've ever seen on this topic has had many omissions and contained much that was apocryphal, or at least wildly inaccurate.

Of course this doesn't exactly lend itself to experimentation.

Screw strength compared to ice temp.

johnnyrig wrote:Here's another thought (as prompted by a friend borrowing a rope, getting pine sap on it, then cleaning it off with isopropyl rubbing alcohol)... Test ropes, slings, etc (nylon and other materials) soaked in various common and not-so-common stuff. Bleach, alcohol, soda, piss, salad dressing, battery acid, cleaning solutions, etc etc. Cordage is cheap, and I bet you could get a lot of old rope donated or very cheap off ebay etc. Only need a couple bollards added to your test rig. Soak overnight, pull 2 to 3 foot sections until failure. Cheap, easy. Now where did I leave that log splitter? I got a test rig to build...

I have already tested a number of those things. Some of the results are available here: rockclimbing.com/cgi-bin/fo…;sb=post_latest_reply;so=ASC;forum_view=forum_view_collapsed;page=unread#unread

In short, battery acid (which is actually 30% sulfuric acid, 70% water) criticaly reduced the strength of the material. Bleach had nearly no short-term effect. The UIAA has done testing on cat piss. They determined the piss reduces the elongation of the material, but not really the strength. I very strongly doubt soda or salad dressing would do anything except make the rope more tasty to eat.

Also, there are companies that sit around all day and expose every chemical thinkable to a number of different materials (including polyamide AKA nylon). You can view these results here: coleparmer.com/Chemical-Res…

That company has probably exposed more chemicals to nylon than every climbing equipment manufacturer combined.

Has anyone seen a test of the effect on the secondary direction of force from the belayer on a static anchor? A single fall load applied to an anchor with fixed length legs (the V+W+8 anchor or just a couple of quickdraws on bolts for example) in a direction that differs from the line of forces created by the anchor will load the anchor biased to one side, but that system assumes that the force applied from the belayer is in the same direction from the anchor as the fall force, but what if it isn't? Since the rope will slide through the anchor point as it is being tentioned will this cause some equalizing effect? This could be taken a step further to see if a belayer could actively equalize the potential fall force by shifting angle to the anchor. Lets say an anchor is equalized straight downward, and a climber's route takes him 10 degrees right of vertical from the anchor, can the belayer simply step out 10 degrees left of vertical to equalize a potential fall in a top rope situation, or shift weight at a belay point to the same effect? I haven't seen a study yet that looks at that aspect of it and I'm guessing real world wouldn't work as it might in a simple climber's theory.

I'd like to thank everyone for there responses. Of all the ideas mentioned, I feel as though the ones with least existing research include bolt strength in wet vs. dry sandstone and screw strength related to continued sun exposure.

I look forward to pursuing these ideas, and I will continue to update the community with my findings. (I'm also wondering how I'm going to get Black Diamond to give me 20 brand new screws...)

Cheers,
-Dylan Weldin

Do you really need 20? I'm guessing the ice will fail before the screws... so couldn't you reuse them?

I would have gone the other way with screw testing and looked at extreme cold.

You can pretty much calc heat transfer in metals & the physical chemistry related to the ice hydrogen bonding as with sun exposure in time. Maybe you can find some spontaneous disorder. You'd be telling us that metals conduct heat to weaken the ice quality; failing the ice anchor at some point in time. Maybe a time-point of diminishing return could be useful; like a top-rope anchor or something directional.